I wouldn’t want to get into a long, drawn out conversation, but I understand where you are coming from and where you are going with this - I think.
I know most of my personal study has been done in this way:
- prayer for enlightenment,
- reading the Scripture for myself - several times - and cross-referencing with other passages to get an accurate understanding.
- use of concordances and lexicons to get the meanings and listings of particular words and phrases.
- use of commentaries and Bible encyclopedias (such as Matthew Henry’s Commentary)
- reference theologians and preachers - early and modern
- trusted Christian brothers and sisters in local assembly (older ones especially)
- local pastors and teachers
And to get to your last points - when they all disagree with one another - what do you do? and, how do you know what is truth?
The simple answer is that I make a choice based on the information, evidence and arguments given and go with the most reasonable and logical conclusions.
I may not know for sure that what I decide on is the absolute truth. But, for me that’s not a problem. Just as you may not know whether or not you are worthy to go to heaven. As that is the fundamental question of your life - it doesn’t seem to bother many Catholics. I don’t sit around and wonder. I leave my mind open to the possibilities.
What I find interesting is what I mentioned before - Catholics don’t have assurance of salvation but that doesn’t seem to disable you from living your life. The same is true for protestants like me who have assurance of salvation but don’t have assurance of every doctrine and teaching that has come down the pike. What will be will be - if my view is wrong in the end then so be it. If I’ve done my best to reconcile my beliefs with the evidence presented, then the ball is in God’s court. He will have to judge. And we would all agree His judgements are just and righteous.
Hope this helps.
Peace…